Model airplane



Jan. 27, 1959 H. A. BERGSTRAND MODEL AIRPLANE 2 Sheets-Sheet 1 Filed March 18, 1957 INVENTOR. H. A. BERGSTRAND ATTORNEY Jan. 27, 1959 H. A. BERGSTRAND 2, 7

' MODEL AIRPLANE Filed March 18, 1957 2 'SheetsSheet 2 INVENTOR. H. A. BERGSTRAND v BY v ATTORNEY 2,370,567 Patented Jan. 27, 1959 ice MODEL AIRPLANE Harold A, B'erg's'trand, East Moline, IlL, assignor to 'strombeck Bec'k'er Mfg'."Co., Moline, Ill.

Application March '18, 1957, Serial No. 646,811

14 Claims. (Cl. 467 6) This invention relates to a toy or model airplane structure and more particularly to structures of the type furnished as an assembly kit.

The problems in this field' are many and complex, primarily because the parts of the kit must not only be such as to be readily assembled by the age group for which intended but must also be capable of adequate functional and structural performance. Added to this is the requirement that the finished model possess a reasonable degree of authenticity. If the model is a flying model rather than merely 'a display piece, it must additionally possess the necessary strength for flying, landing and the inevitable crashes. At the' same time, the necessary strength must be obtained Without adding unnecessary weight.

Accordingly, it is 'apriiicip'al object of the invention to provide an improved-structure of the character described,at'the same time maintaining adequate flyability, reasonable authenticity and low cost. An important object is to improve the wing structure and the wing-tofusela ge assembly, by incorporating therein rigid spar means for tying the wings together via the fuselage. In this respect it is "an object to provide each wing as a hollow structure, preferably by affording in the wing a spar-receiving pocket having a cover 'added after the spar-to-wing assembly is effected. A still further object resides in the use of spacer means between a pair of spars in each wing and the exploitation of the spacer means for the attachment of the landing gear. An overall object of the invention is to provide improvements in the nature of carefully designed bracing components so arranged as not to detract from the appearance of the finished plane. I v

The foregoingand other important objects and desirable features inherent in and encompassed by the inventionwill become apparent as a preferred embodiment is disclosed in the ensuing specification and accompanying sheets 'of drawings, the several figures of which are described below. 7

Figure 1- is a perspective of the assembled model.

Figure '2 isan exploded perspective showing the preassembled relationship among the components of the model.

Figure 3 is an enlarged section on the line 3-3 of Figure 1.

Figure 4 is an exploded perspective of part of the landing gear.

Figure 5is anenlarged fragmentary perspective of the inner edge structure of a wing-as seen when looking generally in'thedirectionofjthe arrow bearing the encircled numeral S'in Figure 1. v

Figure 6 is an exploded perspective of the components shown in Figure 5.

Figure 7 is an enlarged section on the line 77 of Figure 1. y I

Figure 8 is an enlarged section" on the line 8 -8 of Figure 1. s I s As shown in Figure l, the completed model has the 2 typical appearance of airplanes in general, possessing however the scaled-down characteristics of a particular make and design, the identity of which is not material here. The plan e' has the usual fuselage 10, right and left hand wings .12, tail assembly 14, nose cowl 1 6, propeller 18 and landing gear including right and left hand struts 20, wheels 22 and wheel pants 24. Since the right and left hand elements are symmetrical and in some instances identical, only one side of the ship will be described in detail, with reference to the other side where appropriate. s v, i Y X Figure 4 illustrates the pre-assembled components of one-half of the landing gear, this being an instance in which the halves may be identical. The strut 20 has at its upper end a stub provided by notching the strut at 28, 28. In the case shown,'the strut is of light-weight relatively rigid materialsuch as balsa, and the wheel pants, like the wings, fuselage, etc. are of extremely thin material such as polystyrene plastic, here typically vacuum formed to achieve the required configuration. Each wheel 22 is of two complementary halves which complete the wheel when assembled between the pants 24, which are secured to opposite sides of the strut by an appropriate adhesive or cement the nature of which is well known. The specific nature of the Wheels is not significant here. Hubs 30 and axle the landing gear assembly.

The fuselage is here shown as including upper a nd lower complementary halves 34 and; 36, appropriately flanged lengthwise thereof at 33 to afford areas at which the halves are secured together, as by an appropriate cement, to provide a rigid unitary tubular assembly. The lower half 36 has transversely opposed generally upright side walls or portions 40, each having front, and rear slits or apertures 42 and 44 respectively. The paired apertures are of course respectively alinedtransversely to receive spar means, here comprising front and rear spars 46 and 48 which are inserted through the respective apertures to extend outwardly from opposite sides of the fuselage. The opposite outer portions of the front spar are identified at 50 and those of the rear spar at 52. The spars, like the landing gear struts 20, are of balsa, or appropriate light-weight material having greater rigidity than the wing and fuselage material.

The Wing 12-is aone-piece sheet, here polystyreneplastic and vacuum formed to have what may be termed the airfoil section representing generally a true wing (Figure 7). in a substantial portion of the wing by forming the sheet with a depression which-appears in the finished wing'as a pocket or channel 54 which opens upwardly and also opens inwardly at 56 at the inner edge part of the wing,

here comprising a pairof coplanar flanges or Webs'58 and oil separated by the inner pocket opening 56(Figures 5 and 6). The web structure 58-66 affords an area that abuts the fuselage side wall 40, in the zone of the apertures 42 and 44, and is connected thereto, the wall having an arcuate guide ridge 62 for positioning the web area, which ridge receives andcooperates with fore-and-aft alined ribs 64 and 66 respectively on the webs or flanges 58 and (Figures 5, 6 and 8). The lower edge has a lip 61 which furnishes additional cementing area. This lip is substantially coplanar with the surfaces or flanges 58 and 6t] and at any rate is flexible enough to conform to the fuselage side wall (Figure 3). V

The fore-and-aft dimension of the pocket is such that the pocket opening at 5 6 generallyregisters with the fuselage apertures 42-and 44 so as to receive the outer portions 50 and 56 of the spars 46 and 48, the length of the pocket-or its transverse dimension-being suchas to receive or house the spar outer portions. The pocket has a floor 68, upright front and rear walls 79 and 72 pins 32 complete However, the airfoil section is interrupted 3 and an upright outer end wall 74, and the spars are cemented to the front and rear walls and to the proximate portions of the pocket floor. The outer portions of the spars are appropriately shaped to conform to the depth of the Wing pocket 54 and are thus wholly received in the pocket, being concealed from below by the pocket floor 68 and from the outer end by the pocket outer end wall 74.

Concealment of the spars from above is achieved by a wing cover 76, three of the major marginal edges of which are received in and connected to a conforming recess or ledge 78 above the three major sides of the pocket. The fourth or inner edge of the cover is formed as a rib 80 which completes or complements the rib means 64-66 at the inner end of the wing (Figures 5 and 6). The rib 81) of course cooperates with the guide ridge on the fuselage side wall 40 and additionally furnishes an area for cementing to the fuselage and thus increases the strength of the fuselage-towing joint. if desired, the underside of the cover may be cemented to the tops of the spar outer portions 50 and 52.

The wing cover serves a further and vital function other than concealing the spars from above: it completes the airfoil section of the wing (Figures 5, 6 and 7) and when properly assembled the wing has an overall appearance of being of one-piece construction. The hollow or tubular structure afforded by the pocket and cover materially strengthens a major part of the wing, particu larly in its zone proximate to the fuselage and this plus the spars produces relatively extreme strength and rigidity in the midportion of the plane, all with a minimum of added weight.

Further rigidity in this area is achieved in each wing by the use of spacer means, here a foreand-aft block 82, preferably balsa, which spaces the spars apart fore-and aft (Figures 2, 3 and 7) and also serves to mount the proximate landing gear strut 20 via it stub 26, which enters a slot 84 in the pocket floor 68 next to the block 32. In view of the wood-to-wood joint between the block 82 and strut stub 26, glue rather than cement is used, the stub lying alongside and abutting the block (Figure 3) and the strut notches 28 limiting penetration of the slot 8-4 by the stub 26 (Figure 7). The block is glued to the spars and is cemented to the pocket floor before the cover 76 is added, and the cover may be cemented to the top of the block for further strength.

As will be seen, the combinative tubular wing and spar structure has great strength against bending, twisting and warping, and the tie between the wings and across the fuselage insures against fracture of the cemented joints. The use of balsa as structural members facilitates the use of sheet structure for the fuselage and Wings, which sheet material, here polystyrene as already referred to, is easy to handle, lends itself readily to mass production, is decorative and possesses an adequate strengthto-weight ratio for the purpose intended. Securing of the landing gear struts to the spacer block affords strong joints capable particularly of resisting lateral dis placement of the landing gear as Well as forces incurred in landing, etc. Here, as in the case of the spar-to-wing connection, the joints are concealed and thus do not detract from the authentic appearance of the model.

Features other than those elaborated will readily occur to those versed in the art, as will many modifications and variations of the preferred inventive embodiment disclosed, all of which may be achieved without departure from the spirit and scope of the invention.

What is claimed is:

1. In a toy airplane: a fuselage having transversely opposed side walls apertured in transverse alinement; a pair of wings symmetrically arranged respectively at opposite sides of the fuselage, each wing having an inner marginal portion secured to the respective side wall in the zone of the aperture and extending laterally outwardly therefrom; each wing comprising a. one-piece sheet of airfoil section having a portion of said sheet depressed to interrupt said section and affording in said wing an elongated upwardly facing pocket running lengthwise of said wing and opening at said inner marginal portion in register with the proximate side wall aperture; spar means extending transversely through the fuselage via the side wall apertures and having outer portions received respectively in the wing pockets and secured to the wings respectively in said pockets; and a pair of pocket covers secured respectively to the wings and respectively closing the pockets, each cover completing the respective interrupted airfoil section and enclosing the respective outer portion of the spar means from above.

2. The invention defined in claim 1, in which: eachpocket has a floor and said floor has an aperture therein; a supporting member is secured to each wing within itspocket and adjacent to said floor aperture; and a landing gear support extends downwardly from each wing and has an upper portion received in the respective floor aperture and secured to the supporting member.

3. The invention defined in claim 1, in which: the marginal portion of each wing comprises a: fore-and-aft web having face-to-face contact with the proximate side wall of the fuselage, said web being interrupted to afford register of the wing pocket with the respective side wall aperture.

4. The invention defined in claim 3, in which: the junction of the web and airfoil section of each wing sheet includes a fore-and-aft upstanding rib secured to the respective side wall of the fuselage to increase the area of contact, said rib being interrupted in conformance with the pocket, and each Wing cover has an inner marginal rib completing the proximate wing rib and secured to the proximate side wall of the fuselage.

5. The invention defined in claim 1, in which: each wing pocket cover is of sheet-like material secured at its marginal edges to the wing sheet at the portions thereof defining the upper margin of the pocket, and each sheet includes a ledge along said upper margin of the pocket and stepped down below the top surface of the airfoil section by an amount substantially equal to the thickness of the wing cover to accommodate the marginal edges of said cover.

6. in a toy airplane: a fuselage having transversely opposed side walls, each side wall having front and rear apertures and said apertures in one wall being respectively alined transversely with those in the other wall; a pair of wings symmetrically arranged respectively at opposite sides of the fuselage, each wing having an inner marginal portion secured to the respective side wall and extending laterally outwardly therefrom; each wing comprising a one-piece sheet of airfoil section having a portion of said sheet depressed to interrupt said section and affording in said wing an elongated upwardly facing pocket running lengthwise of said wing, each sheet providing its pocket with a laterally extending upright front wall, a laterally extending upright rear wall and a floor joining said walls, said front and rear walls being spaced apart fore-and-aft on the order of the spacing of the front and rear apertures in the respective side wall and said floor lying below said apertures so that said apertures open outwardly to the pocket; a front spar extending transversely through the fuselage via the front apertures and having outer portions received respectively in the pockets and secured respectively to the front walls of said pockets; 2. rear spar extending transversely through the fuselage via the rear apertures and having outer portions received respectively in the pockets and secured respectively to the pocket rear walls; and a pair of pocket covers secured respectively to the wings and respectively closing the pockets, each cover completing the respective interrupted airfoil section and enclosing the respective outer portion of the spars from above.

7. The invention defined in claim 6, including: foreand-aft spacer means in each pocket and interposed between the front and rear spars to maintain the fore-andaft spacing of said spars.

8. The invention defined i :1 claim 7, in which: each pocket floor has an aperture therein adjacent to its spacer means; and a landing gear support depends from each wing and has an upper portion extending through the respective floor aperture and secured to the respective spacer means.

9. The invention defined in claim 6, in which: the marginal portion of each wing comprises a fore-and-aft web having face-to-face contact with the proximate side wall of the fuselage, said web being interrupted to conform to the associated wing pocket so as to expose the proximate side wall apertures to said pocket.

10. In a toy airplane: a fuselage having transversely opposed side walls, each side wall having front and rear apertures and said apertures in one wall being respectively alined transversely with those in the other wall, a pair of wings symmetrically arranged respectively at opposite sides of the fuselage, each wing having an inner marginal portion secured to the respective side Wall in the zone of the apertures and extending laterally outwardly therefrom; each wing comprising a one-piece sheet of airfoil section having a portion of said sheet depressed to interrupt said section and affording in said wing an elongated upwardly facing pocket running-lengthwise of said wing and opening at said inner marginal portion in register with the proximate side wall apertures; a front spar extending transversely through the fuselage via the front apertures and having outer portions received respectively in the pockets and secured respectively to the wings thereat; a rear spar extending transversely through the fuselage via the rear apertures and having outer portions received respectively in the pockets and secured respectively to the wings thereat; and a pair of pocket covers secured respectively to the wings and respectively closing the pockets, each cover completing the respective interrupted airfoil section and enclosing the respective outer portions of the spars from above.

11. In a toy airplane: a fuselage having generally transversely opposed side portions apertured in transverse alinement; a pair of wings extending oppositely outwardly respectively from said side portions, each wing comprising a sheet having an inner fore-and-aft end part secured to the proximate side portion of the fuselage and said edge part being constructed to afford an opening alined with the side portion aperture, said Wing sheet having a downwardly depressed portion providing a transversely elongated vertically opening pocket alined with said inner end part opening; spar means extending transversely through the fuselage apertures and through the inner end part openings and having opposite outer end portions received respectively in the wing pockets and secured to the wings in said pockets; and a pair of wing covers, one secured to each wing and closing the pocket of said wing.

12. In a toy airplane: a fuselage having transversely opposed side walls apertured in transverse alinement; a pair of wings symmetrically arranged respectively at opposite sides of the fuselage, each wing having an inner marginal portion secured to the respective side wall in the zone of the aperture and extending laterally outwardly therefrom; each wing comprising a one-piece sheet of airfoil section having a portion of said sheet depressed to interrupt said section and affording in said wing an elongated upwardly facing pocket running lengthwise of said wing and opening at said inner marginal portion in register with the proximate side Wall aperture; and spar means extending transversely through the fuselage via the side wall apertures and having outer portions received respectively in the wing pockets and secured to the wings respectively in said pockets.

13. In a toy airplane: a fuselage having transversely opposed side walls, each side wall having front and rear apertures and said apertures in one wall being respectively alined transversely with those in the other wall; a pair of wings symmetrically arranged respectively at opposite sides of the fuselage, each wing having an inner marginal portion secured to the respective side wall in the zone of the apertures and extending laterally outwardly therefrom; each wing comprising a one-piece sheet of airfoil section having a portion of said sheet depressed to interrupt said section and affording in said wing an elongated upwardly facing pocket running lengthwise of said wing and opening at said inner marginal portion in register with the proximate side wall apertures; and a front spar extending transversely through the fuselage via the front apertures and having outer portions received respectively in the pockets and secured respectively to the wings thereat; a rear spar extending transversely through the fuselage via the rear apertures and having outer portions received respectively in the pockets and secured respectively to the wings thereat.

14. In a toy airplane: a fuselagehaving transversely opposed side walls apertured in transverse alinement; a pair of wings symmetrically arranged respectively at opposite sides of the fuselage, each wing having an inner marginal portion secure to the respective side of the fuselage in the zone of the aperture and extending laterally outwardly therefrom; each wing including a sheet portion at least in part of airfoil section having a depressed part providing in said wing an elongated upwardly facing pocket running lengthwise of said wing and opening at said inner marginal portion in register with the side wall aperture at that side of the fuselage; spar means extending transversely through the fuselage via said apertures and having outer portions received and mounted respectively in the pockets; and a pair of pocket covers mounted respectively on the wings and closing the respective pockets.

References Cited in the file of this patent UNITED STATES PATENTS 1,889,982 Full Dec. 6, 1932 2,182,913 Brubaker Dec. 12, 1939 2,399,130 Mathee et al. Apr. 23, 1946 2,542,042 McCoy Feb. 20, 1951 2,608,025 Miller Aug. 26, 1952 

